Clutch mechanism for buttonhole-sewing machines.



No. 718,569. PATBNTED JAN. 13,1903.

W. W. DIXON.

CLUTCH MECHANISM FOR BUTTONHOLE SEWING MACHINES.

APPLIUATION FILED APR. 29, 1898.

N0 MODEL.

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WILLIAM W. DIXON, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO REEOE BUTTON HOLE MACHINE COMPANY, OF PORTLAND, MAINE.

CLUTCH MECHANISM FOR BUTTONHOLE-SEWING MACHINES.

SPECIFICATION forming part of Letters Patent No. 718,569, dated January 13, 1903.

Application filed April 29, 1398. Serial No. 679,176. (No model.)

T0 at whom it may concern:

Be it known that I, WILLIAM W. DIXON, of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Clutch Mechanism for Buttonhole Sewing Machines, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention is intended as an improvement on the class of clutch device shown and described in United States Patent No. 367,063;

dated July 26, 1887, and granted to John Reece. The clutch device shown in said patent is composed of'a clutch-lever having a projection which is disengaged from a camring carried by the loose pulley of said clutch when said shaft is to be left at rest and by the end of said clutch-lever striking against a rigidly-held projection extended from an arm of a rook-shaft in the path of movement of said lever.

The clutch-lever in operation is rotated at a very high speed, and it happens at timesthat the blow is so quick and of such short duration that the said clutch-lever slips past the projection on the arm and is not arrested, so that the machineis not instantly stopped, the needle being thereby bent or broken or the work-clamp being injured by the descending needle. I have improved the clutch device referred to by providing the said arm with a spring-held or dragging projection, said projection when struck by the clutchlever yielding somewhat to the movement thereof, but not yielding until after the clutch-lever has been fully engaged by the projection, the said projection acting to hold onto the end of the clutch-lever for a short time after the lever has been moved, thus prolonging or lengthening the time of engagement between the projection and the clutch-lever sufficiently to insure the release of the pulley. With this construction it is impossible for the clutch-lever to slip back into engagement with the shoulder on the cam-ring before the projection becomes disengaged from the end of said clutch-lever, for the dragging action of the projection against the clutch-lever lengthens the time of engagement between the said projection and clutchleve'r sufficiently to positively insure suflicient movement of the clutch-lever to certainly disengage it from the cam-ring, and thus stop the machine.

My dragging projection is shown as composed of an L-shaped bar, the shank of the bar entering a socket carried by a rockerarm, a strong spring keeping said projection seated in the said arm in operative position.

. Figure 1 of the drawings shows a clutch device With my improved dragging projection in position. to be acted upon by the clutch- ]ever in its rotation to disengage the same. Fig. 2 is an outer side view of the loose pulley and its cam-ring, the projection on the end of the arm b being shown in section and in operative engagement with the cam-ring, as when the pulley is driving the shaft; and Fig. 3 is a view looking at the inner side of the loose pulley, chiefly to show the spring connected with the cam-ring.

The clamp-frame A the stitching-frame A, the main shaft 11, on which is loosely mounted the continuously-running belt-pulley M, the cam-groove 24. (see Fig. 2) in the said pulley, in which operates the projection a on one end of clutch-lever b the hub a splined to the shaft a and to which said clutch-lever b is pivoted at 0, the spring 6, connected with said clutch-lever and with a Stud 6, fast on the hub a, the rock-shaft a, having attached to it an arm d and also the arm 5 said arm 6 carrying a projection adapted to cooperate with the clutch-lever b when it is desired to stop the rotation of the shaft Ct, are and may be all substantially as shown in the said patent, the said parts operating substantially as provided for in the said patent.

When the clutch is in operative position to rotate the main shaft afrom the continuouslyrunning beltpulley (1 the projection a which stands at right angles to the inner end of the clutch-lever b and which plays in the cam-groove 01 is in contact with the shoulder Z2 upon the cam-ring a as illustrated in Fig. 2.

The cam-ring, it will be remembered, is fast and rotative with the pulley a and the rotation thereof, which is in the direction opposite to the hands of the clock, will through the engagement of the projection a and shoulder I) carry the clutch-lever 11 around with the said cam-ring, and since the clutchlever b is pivotally mounted on the hub a, which is splined to the shaft a, such rotation of the clutch-lever b will operate to rotate the main shaft (1.

In the patent above referred to the arm b carries at its end a rigid projection I), which at certain intervals, as when the buttonhole is completed and it is desired to stop the rotation of the stitching mechanism, is thrown forward toward the clutch mechanism by the springf, which spring is secured to the end of the arm 11 and to any suitable fixed part of the frame. This inward movement of the arm 19 brings the projection b into the path of the outer end of the clutch-lever b, with the result that as the outer end of said cl utchlever b impinges against the projection b the clutch-lever is rocked on its pivot a to thereby disengage the projection a from the shoulder b, whereby the pulley (t and camring a may rotate without effecting the clutch-lever b the projection a of said clutch-lever 11 playing in the cam-groove 24.

The operation of the parts above described is fully set out in the patent above referred to, and further description thereof is not deemed necessary herein.

In the present instance the arm b has an extended arm n, as provided for in United States Patent No. 488,028, granted to John Reece on December 13, 1892, the function of said arm being the same as in said patent, and the rock-shaft a is turned at proper times by usual devices, such as a rod n which is fully shown and described in United,

States Patent No. 544,827, granted to John Reece August 20, 1896, to allow the spring f to throw the arm b toward the shaft a when the constantly-running pulley a is to be released from the shaft a to leave the stitching mechanism at rest;

The pawl g, which is pivoted at g upon th arm I) and is controlled by the spring 9 cooperates with a suitable notch g' to prevent recoil or backward rotation of the shaft (1 when the clutch mechanism is thrown out as described in United States Patent No. 367,063, above referred to.

Myinvention herein illustrated consists in so modifying the clutch mechanism above described that the projection carried by the end of the arm I) is a yielding or a dragging projection, in order that when the said projection strikes the clutch-lever Z) it will yield at the time of engagement between the said projection and the clutch-lever, so that the said clutch-lever will not be disengaged from the said projection until after the projection a on'the inner end of the clutch-lever b is fully disengaged from the shoulder b on the cam-ring. To accomplish this result, I have provided the end of the arm b with a guideway D, suitably shaped to receive the shank D of a projection D the said shank being shown chiefly in dotted lines in the drawings and the said projection having a connected stud D to which is attached a strong spiral spring D the opposite end of said spring being attached to a suitable stud D fast on the guideway. With this construction it will'be noted that the projection D can yield slightly when engaged by the clutch-lever b and in the operation of the device when the arm I) is moved toward the shaft and the projection D is brought into the path of movement of the clutch-lever 19 so that one end of said lever meets said projection, the latter yields slightly to the impact of the blow, and in so yielding slightly it remains longer in engagement with the end of said clutch-lever b, the engagement being sufficient to drag and hold onto the said clutch-lever, so that it is under all circumstances positively disengaged from the ring a thus freeing the loose pulley, letting it run on the said shaft at until the arm b is again moved in the opposite direction to remove the projection from the end of the clutch-lever.

This invention is not intended to be limited to the exact shape of the projection D referred to, and my invention is intended to cover any movable projection carried by said arm 12* and normally held in position by a strong spring, it being obvious that the projection might be in the shape of a lever instead of a sliding projection, as illustrated.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In a clutch mechanism, a shaft, a continuously running pulley loose thereon, a clutch-lever rotative with the shaft and adapted to clutch the pulley thereto, and means to operate the said clutch-lever to disengage the pulley from the shaft, when it is desired to stop the rotation of said shaft, said means comprisinga pivotally-mounted arm,aprojection yieldingly carried by the arm, and means to rock said arm to bring the yielding projection thereon in the path of the end of the clutch-lever, whereby the yielding projection prolongs the time of engagement between the same and the clutch-lever sufficiently to insure the disengagement of the pulley.

2. In a clutch mechanism, a shaft, a continuously running driving pulley loosely mounted thereon, said pulley having a camring rotative therewith, a clutch-lever pivotally mounted upon said shaft and adapted to engage the cam-ring to drive the shaft, a pivoted arm, a projection carried by said arm and movable with relation thereto, a spring on the arm and engaging the projection, and means to rock said arm to bring the projection thereon into the path of the end of the clutchlever, said projection yielding when engaged by the clutch-lever whereby the time of engagement between the projection and lever is prolonged sufiiciently to insure the disengagement of said clutch-lever from the cam-ring.

3. In a device of the class described, a rotary clutch-lever, amovable arm, aprojection carried by the arm and capable of movement relative thereto, and a spring mounted on the arm and engaging said projection, the movement of'the arm operating to place the projection in the path of movement of the clutchlever.

4. In a device of the glass described, a rotary clutch-lever, a movable arm having a guideway, a projection having a shank received by said gnideway, and a spring connecting said shank and arm, the movement of the arm operating to place the projection in the path of movement of the clutch-lever.

5. The combination with a clutch including WILLIAM DIXON.

Witnesses:

GEO. W. GREGORY, MARGARET A. DUNN. 

